Sealing and pumping means and methods environmentally leak-proof pump with misting chamber defined therein

ABSTRACT

An environmentally leak-proof pump is provided including: an environmentally leak-proof motor housing having located therein a motor for rotatably driving a rotating shaft; a piston seal axially forward of the motor; and an oil misting chamber disposed between the motor and the piston seal, the misting chamber for simultaneously providing lubrication to two coaxially disposed spaced apart bearings. The oil mister (34) includes a dispenser (260) fixed to a rotating shaft (23), the dispenser having a plurality of nozzles formed by bores (262 and 263) on opposing sides of the dispenser body. Each bore communicates with a passageway (264) thus allowing each nozzle to continuously direct a flow of lubricating liquid or mist toward adjacent bearings (35 and 36).

This application is a division of application Ser. No. 07/803,007, filedDec. 4, 1991, which was allowed on Jun. 22, 1993.

FIELD OF THE INVENTION

This invention relates to new and improved pump protection systems andcomponents thereof for isolating a pump motor and surroundingenvironment in which the pump is used, from a fluid pumped.

BACKGROUND OF THE INVENTION

Pumps are often used in conjunction with gases or liquids such as acids,oils, and toxins which can cause serious harm to the environment if theyescape. Thus, when pumping a dangerous liquid from one location toanother, it is important that neither the liquid nor gas which is oftenreleased by the liquid, escape to the atmosphere or pump areas outsidethe desired fluid pumping path.

In the 1930's mechanical seals were developed to overcome prior pumpshaft sealing problems. This permitted a more secure seal againstliquids from escaping along the shaft of the pump. However, in somecases liquid escaped when the pressure within the pump became too highfor the seal to handle. The competing interests of maintaining anefficient pump and a safe pump required appropriately balancing the tworequirements. Predicting the amount of safety required could only bebroadly approximated based on the type of liquid to be pumped. The morehazardous the liquid, the more secure the seals.

The other problem with the mechanical seals of the 1930's was that thegases which were produced by the liquids were not always stopped. Theseals were often easily permeated by the vapor. One solution to thisproblem was the creation of an arrangement known as a double seal with abarrier fluid protection. In this arrangement, the two seals form acavity which is then filled with a clean fluid. The seal facing theexcess liquid, that which does not exit the pump where desired, inhibitsthe movement of the liquid sufficiently to prevent passing of theliquid. The vapor which can permeate the seal is stopped by the cleanfluid in the cavity.

One of the problems with this double seal system was that any failure bythe first seal could defeat the protection system. Either gases from theliquid could then escape through the barrier to the environment or theliquid could break through the second seal. This would sometimes ruinthe motor and the therefore the pump. A failure of the second seal priorto failure of the first seal would result in the same problems. Byallowing the clean fluid to escape from the cavity, the atmosphere wouldeffectively be on the other side of the first seal, the only remainingworking seal. The breaking of seals was a problem since the fluid withinhad to be maintained at a high pressure to be effective, or at least apressure higher than the pressure of the liquid being pumped.

Some development in the field created pumps in which the motor wasentirely within the pump housing. One type is known as the canned motorpump. Here, the motor could fail for many reasons. Sometimes corrosiveliquids would affect the motor. Also, the bearings of the motor as wellas other motor parts could clog which increased downtime of the system.This type of pump further was not desirable for use with very hot ordirty liquids. Finally, the efficiency of the system could be lowerbecause the rotating parts of the motor would have to turn within aliquid which caused additional friction during operation. Even higherfriction forces occurred because sleeve bearings had to be used insteadof ball bearings, since the liquid pumped filled the bearing area.

The use of magnetic pumps was an attempt to solve many of the problemsby having the pump housed entirely within a single body and driven by amotor surrounding the body. The motor and pump are magnetically coupled,one magnet is attached to the motor and a magnet of opposite polarity isattached to the pump within the body. However, the magnet pump has thesame problem as the canned motor pump with respect to the bearings alsoexposed to the liquid which is being pumped by the machine. Furthermore,the magnetic pump often generates a lot of heat which is difficult tocool sufficiently to prevent meltdown of the pump. The efficiency inoperating a magnetic pump can be quite low because of the loss of energyin transferring the motor movement magnetically through the body to thepump shaft.

SUMMARY OF THE INVENTION

The principle object of the present invention is to provide a pump whichenables the user to efficiently and safely pump hazardous and otherfluids.

Another object of the present inventions is to provide a pump wherebythe motor is protected from any fluid that might attempt to enterthrough the pump system.

It is still a further object of the present invention to provide a pumpthat has plural seals, preventing the escape along a shaft axis ofliquid or gas, which seals may be adjusted during use.

It is still a further object of the present invention to provide arepeller assembly useful in a pump, wherein the repeller has a doubledisk and vane arrangement which reverses the direction of escapedliquid.

It is still a further object of the present invention to provide atriplex seal arrangement and components thereof, wherein the triplexseal is adjustable to act as a barrier and prevent escape of variousfluids under a wide range of pressures.

It is still a further object of the present invention to provide apiston seal arrangement barrier enabling the user to manually orautomatically adjust the pressure on the seal within a pump or othermechanism having a rotating shaft to be sealed.

It is further object of the present invention to provide a lubricatingassembly to properly lubricate a bearing system in a mechanicalarrangement having bearings surrounding a rotating shaft.

It is further object of the present invention to provide a pump having afan assembly mounted on a housing while magnetically coupled to anenvironmentally sealed motor within the housing for cooling the motorduring operation of the pump.

It is a further object of this invention to provide safe and efficientrotary shaft sealing methods as pumping methods.

The pump construction of the present invention comprises a pump body orcasing housing a motor and a rotatable drive shaft connected thereto,with an impeller for pumping and expelling pump liquid or gas beingpumped. A repeller and a triplex seal act as axial flow preventingbarriers. Preferably the pump has, in addition, a piston seal in serieswith the triplex seal along the drive shaft, with both seals acting asbarriers to fluid passing by the impeller. The pump is, preferably,constantly and automatically lubricated by an oil mister. Finally, themotor is, preferably, magnetically coupled to a fan assembly for coolingthe motor.

According to the invention, the pump arrangement or construction,preferably, has an impeller for impelling of fluid through the pump andthe impeller is mounted on an axially extending drive shaft. A repeller,comprising a circular flange, is fixed in position on the shaft to sealthe shaft against fluid flow from the impeller. The repeller acts as abarrier, although not forming a full seal. The repeller, preferably, hasa plurality of radially extending vanes defining a plurality ofsubstantially enclosed channels, each defining a radially extendingopening on a surface thereof. The channels are sized and shaped toprovide a volute channel for attenuating swirling fluids passing fromthe impeller to the repeller and to reverse directions of at least someof the fluids.

A preferred seal construction for sealing the rotating shaft of the pumpalong a central axis of the shaft has a sealing flange or disc fixed tothe shaft for rotation therewith. The flange carries a circular sealingsurface on a first side. The sealing surface is in sliding contact at afirst mating surface, with a second mating sealing surface formed by asealing tube, so that a sliding fluid seal is formed at the matingsurfaces of the sealing surface and sealing tube. The seal acts as abarrier to fluid contained in the pump and prevents flow along theshaft. The tube is operatively associated with a pressure applyingsurface which determines closing force of the seal, with that surfacebeing positioned opposed to the second sealing surface. A flexiblediaphragm, having at least two positions for respectively enlarging ordecreasing the surface area of the pressure applying surface isprovided, with the sealing tube attached thereto and being fixed againstrotation about the axis of the seal and movable along the axis, toprovide for sealing pressure at the mating sealing surfaces. Thediaphragm defines, in part, a backup chamber for the sliding rotaryseal.

In a preferred embodiment, the rotary seal includes monitoring means ina backup chamber, for allowing liquid or gas access and egress from thechamber, and for measuring pressure within the backup chamber.Preferably, a plurality of fixed stops limit the two positions of theflexible diaphragm.

In the most preferred embodiment, the seal is a triplex seal andcomprises a plurality of three coaxial tubes having three slidingsurfaces defining two backup chambers. At least one flexible diaphragmarrangement is provided for giving the flexibility of predetermining theseal closing pressure by determining predetermined fixed positions ofthe diaphragm to vary the backup pressure surface and, therefore, effectsealing pressure. In this manner, sealing pressure can be minimizedwhile providing for desired sealing with minimized frictional contact.

A method of sealing a rotating shaft against axial flow of liquids therealong, comprises providing a circular flange fixed on a drive shaft,with a first sliding, enclosing sealing surface on the flange, and tubemeans having a mating surface for contact with the sliding surface. Thetube means is provided with a pressure applying surface and diaphragmmeans for varying pressure on the pressure applying surface. Fluid onone side of the flange applies a sealing pressure and the sealingpressure is modified to actually compress the tube against the flange toform a sliding seal, which modification is carried out by properselection of diaphragm position to vary a pressure applying surface.

According to the invention, a pump comprises a pump shaft having acentral axis and flange fixed to the shaft carrying a circular sealingsurface thereon forming a mating seal surface. A spring loading sealingtube is resiliently urged toward the first mating seal surface and thetube defines a rear surface for defining a sealing pressure on the sealsurface. The tube is stationary with respect to axial rotation about theaxis, but is resiliently fixed for movement along said axis caused bypressure on the pressure applying surface. A fluid reservoir has adefined volume and means for varying the volume or pressure of fluid tovary hydraulic pressure in the fluid reservoir and, therefore, vary thesealing pressure.

A mechanism is provided for simultaneously providing lubrication to twocoaxially located, spaced apart, substantially coaxial rotary bearingsmounting a shaft such as a pump shaft. A dispenser is mounted coaxiallywith the coaxially aligned rotating bearings. The dispenser rotates in aliquid reservoir and has means for entraining a liquid from thereservoir and bringing liquid to nozzles provided on the dispenser, todispense the liquid from the nozzles directly to each of the rotarybearings. Plural nozzle means direct the fluid in the direction desiredand preferably act as misters to mist the lubricating fluid. Thedispenser can use a plurality of bristles as nozzles, or can haveoppositely directed nozzles to preferably provide just the lubricationnecessary and no over supply of liquid which might tend to obstruct thebearings. The bearings can be sealed so that no outside contaminants areexposed to the bearings.

An enclosed pump motor construction has a magnetic means mounted on amotor shaft for rotation thereabouts. An environmentally leak-proof,non-magnetic casing enclosed the motor and motor shaft with a coolingfan being independently mounted for free rotation on an axis coaxialwith the axis of the motor workshaft and is located outside of thecasing. The cooling fan means carries a second magnetic means forcoupling with the first magnetic means to turn therewith when the motorshaft is rotated, whereby the pump motor is cooled by direct flow fromthe cooling fan.

In still another rotary seal for rotating shafts, a disc is fixed to theshaft for rotation therealong. The disc defines a first sealing surfaceencircling the shaft. A tubular member is coaxially located with respectto the shaft and stationary about the axis of rotation of the shaft, butmounted for movement along the shaft by resilient means to engage thefirst sealing surface at a second sealing surface of the tube. The tubehas a rear pressure applying surface opposed to the seal surface and afluid chamber contacts the pressure applying surface. Means are providedfor varying pressure in the chamber to vary the sealing pressure at thesealing surface of the disc and tube. Preferably, the chamber is filledwith a fluid and the fluid pressure is varied by the use of a reciprocalpiston. The piston can be reciprocated by a screw cap, as desired, toobtain the desired sealing pressure.

Pumps in accordance with the invention use one or more of the seals ofthis invention. In the most preferred embodiment, a pump constructionhas a repeller means, triplex seal, piston seal and isolated fan meansin accordance with this invention.

It is a feature of this invention that dangerous fluids can be easilypumped, utilizing one or more of the features of the present inventionand, preferably, all of them in a preferred pump construction. Aleak-proof pump is obtained which can meet critical emission controlsset out by substantially all environmental protection and governmentlaws. The triplex seal, in particular, acts as a positive seal againstfluid pressures of from 0 p.s.i.a, to 425 p.s.i.a. along the axis of theshaft. Thus, the most difficult seal, i.e., the first fluid seal afterthe repeller, is of novel construction which permits good sealing, yetminimized friction by proper preselection of sealing pressure. Thetriplex seal can be monitored to determine pressure in a backup chamberthereof. Automatic pump shut-down can be carried out if monitoringuncovers a pressure change that indicates fluid leakage. The triplexseal and variants thereof can be used as shaft seals in a number ofdifferent end uses. The repeller used can vary greatly, although thepreferred construction provides a good means for reversing a substantialamount of flow towards the impeller in the pump arrangement of thepresent invention.

Because the pumped liquid never enters the bearing chamber and becausethe rotary bearings can be lubricated by the dispenser, full ball orroller bearings can be used, rather than conventional sleeve bearings.This permits maximum thrust and radial load resistance for longer pumplife and lower heat generation. Because the triplex and pump seals arebarriers, pump fluids do not pass to the bearings and the pumps of thisinvention can pump particle carrying fluids that would otherwisecontaminate the bearings.

The second seal, having a piston acting to provide sealing pressure,provides good backup protection in an environmental pump, as does theseal obtained by encasing the motor and providing for cooling outside ofthe flow path of the pump and outside of any leakage flow path of thepump. In spite of the many seals and positive flow barriers provided bythe pump of the present invention, pumps can vary in size and purposefor a wide variety of purposes, including pumping of acids, bases,gases, compression of gases and the like. Moreover, such pumps can beconstructed using substantially conventional construction techniques atminimized cost and expense, with high reliability and accuracy, usingconventional motors, bearings, impellers, casings and the like.

These and other objects and features of the present invention will bebetter understood and appreciated from the following detaileddescription of basic embodiments thereof, selected for the purpose ofillustration and shown in the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal cross-sectional view of the pump;

FIG. 2 is cross-sectional view of the pump taken along line 2--2 in FIG.1;

FIG. 3 is an enlarged fragmentary end view through line 3--3 of FIG. 1,showing an end of the repeller;

FIG. 4 is an enlarged fragmentary longitudinal cross-sectional view ofthe impeller portion;

FIG. 5 is an enlarged fragmentary longitudinal cross-sectional view ofthe triplex seal arrangement;

FIG. 6 is an enlarged fragmentary longitudinal cross-sectional view ofthe piston seal arrangement;

FIG. 7 is an enlarged fragmentary longitudinal cross-sectional view ofthe oil mister;

FIG. 8 is a cross-sectional view of the oil mister taken along 8--8 inFIG. 7;

FIG. 9 is cross-sectional view of a portion of the oil mister takenalong 9--9 in FIG. 8;

FIG. 10 is an enlarged fragmentary longitudinal cross-sectional view ofa second embodiment of the oil mister;

FIG. 11 is a cross-sectional view of the second embodiment of the oilmister taken along 11--11 in FIG. 10;

FIG. 12 is cross-sectional view of a portion of the second embodiment ofthe oil mister taken along 12--12 in FIG. 11;

FIG. 13 is an enlarged fragmentary longitudinal cross-sectional view ofa third embodiment of the oil mister;

FIG. 14 is a cross-sectional view of the third embodiment of the oilmister taken along 14--14 in FIG. 13;

FIG. 15 is an enlarged fragmentary longitudinal cross-sectional view ofthe motor fan arrangement.

DETAILED DESCRIPTION

A preferred embodiment of a pump in accordance with the inventionintended for very high speed pumping of hazardous liquids such as acidsand the like, is shown at 20 in FIG. 1. The principle components of thepump 20 comprise an electric motor 1 within an overall casing 22, havinga drive shaft means 23 connected at one end to the motor 21 and at theother end to an impeller assembly 25 mounted within the composite,overall, body casing 22.

Three barrier means comprising a repeller assembly 30; a triplex sealarrangement 31; and a piston seal arrangement 32. Each barrier means iscoaxial with the drive shaft means or motor drive shaft 23, and isarranged in longitudinal alignment serratim between the impellerassembly 25 and the motor 21. The barrier means function to controlliquid or gas from undesired contact with either the motor 21 or theenvironment in which the pump 20 is used. The combination of therepeller assembly 30 and the impeller assembly 25 forms the wet end ofthe pump 20, shown at the right hand side of FIG. 1. At the left handside of the pump 20, as shown in FIG. 1, a fan assembly 33 ismagnetically coupled to the motor drive shaft for coaxial rotationtherewith.

An oil mister assembly 34 is positioned between the barrier means andthe motor 21, providing lubrication to rotary bearing assemblies 35, 36which support the shaft 23.

Turning now to a description of each section of the pump 20 starting atthe wet end, the impeller assembly 25 is best illustrated in FIGS. 1-3.A volute 40 is formed by metal casing portion 41 and inwardly extendingbackplate 42 defining a chamber 43 having a longitudinal extendingopening forming an inflow path 44 for liquid and an upwardly extendingoutflow path 45. As liquid flows into the volute 40 through the inflowpath 44, a disc shaped impeller 46 forces a substantial portion of theliquid through the outflow path 45.

The impeller 46, as shown in FIGS. 1 and 2, is a conventional closedimpeller. In such an arrangement, the circular disc or flange shapedimpeller is coaxially mounted on drive shaft 23 and includes a pair ofcircular facing plates, coverplate 47 and rearplate 48, with a pluralityof curved radiating vanes 49 interconnecting the plates 47 and 48. Thevanes 49 extend in a parabolic pattern from a domed center hub orcylindrical flange 50 of the impeller plates. The domed center hub 50helps reduce the turbulence created by the high pressure liquid as itenters the volute 40. The rear plate 48 has a part of hub 50 which isthreaded to engage a threaded portion 51 of the shaft outer end 52.Thus, the impeller 46 is coaxial with and rotates at the same rate asthe shaft 23 as does the repeller.

The impeller assembly casing 53 encloses the impeller and is attached toan inflow pipe 55 at bolted, circular flange 54, an outflow pipe 55A atbolted, circular flange 56 and the overall casing 22 by a boltedcircular flange 58 through eight circularly arranged screw thread bolts57.

A screw threaded drain plug 59 and associated drainage port is mountedto allow through draining of the impeller assembly throughout the pump20 drain plugs or fluid ports 59-63 allow for complete draining,cleaning and/or filling of their associated casing sections.

In the present embodiment, the impeller assembly 25 meets theapproximate performance specifications of standard pump of ANSI/ASMEB73.1M-1984. The impeller assembly 25 measures 3×1.5×8 inches. Thus, theimpeller diameter for this configuration is a maximum eight inches. Insuch an arrangement, there are usually four or five vanes 49equidistantly spaced around the impeller, however, four vanes are shownin this embodiment. If desired, conventional back pump out vanes, suchas radially extending back pump out vanes 86 (shown in dotted outline inFIG. 2), can be used. Such vanes are conventional and, as known, extendfrom the motor side face of rear plate 48 and tend to prevent flowtoward the repeller as the impeller rotates. The pump as herein claimed,is not intended to be limited to either the ANSI standards or the APIstandards.

After use of the pump 20, the system can be emptied of any liquid or gasremaining within the body or casing 22. This is accomplished by openinga plurality of drainage ports or plugs 59-63 located on the bottomportion of the body 22.

While most of the liquid being pumped will exit the pump 23 through thevolute outflow path 45, some of the liquid may pass behind the impeller46 into a narrow passageway 64 shown by arrows in FIG. 4 extending fromthe wet end of the pump toward the fluid chamber or reservoir 87 beforethe triplex seal. This passageway 64 is formed by the combination of theimpeller 46 and repeller assembly 30 and a plurality of inwardlyextending, circular, coaxial stationary body backplates 42, 65 and 66.

After the pumped liquid enters the passageway, it travels down the firstvertical portion, as seen in FIGS. 1 and 4, between the rear impellerplate and the backplate 42. The centrifugal force exerted by therotation of impeller 46 swirls the entering liquid and expels it out andback into the volute and eventually out pipe 55A.

Under sufficient pressure, some of the liquid moves rearwardly within afirst horizontal portion 65 formed by the impeller hub or collar 50 andthe backplate 42. The backplate 42 also forms one of the walls of avertical portion of the passageway 64 along with a first circularextending flange or disk 70 acting as a repeller of the repellerassembly 30. The first disk 70 is fixed to the motor shaft 23 forrotation therewith and is perpendicular to the axis of the shaft. Aparallel, substantially identical second disk 71 is integral with arepeller mounting element 72 which encases a substantial portion of theimpeller collar 50 and is fixed with and coaxially mounted on the shaft23.

The mounting element 72 and the backplates 42, 65 and 66 form horizontalportions of the passageway 64 that has unwanted fluid flow from theimpeller past the repeller. Horizontal fluid passageway portions arefurther defined by a longitudinal segment backplate 42 and disk members70 and 71. Vertical repeller passageway portions 75 through 77 of thepassageway 64 are defined by the disk members 70 and 71 and thebackplates 42, 65 and 66.

The labyrinth shape of the passageway 64 at the repeller section aloneis a difficult obstacle for the liquid to overcome in order to reach themotor 21. The upward, downward, and horizontal passageway elongates thedistance the liquid must travel through the pump to cause damage orhazard at the motor or beyond in the atmosphere. Because liquid followsthe path of least resistance, it will tend to remain in the volute 40rather than traverse the vertical portions of the impeller passageway.One structure useful to achieve this labyrinth shape and minimizeleakage passage ways, is use of a solid one piece construction for thedouble repeller element 72 combined with a split backplate 65. This alsoallows ease of assembly and perfect alignment and repeller separation.

In addition to the shape of the impeller passageway, other structuresprevent the liquid from reaching the motor 21. Each repeller disk member70 and 71 has a radial extending vane arrangement 80 and 81,respectively, located on a disc or flange face or side facing away fromthe impeller 46. In each of the vane arrangements 80 and 81, adjacentvanes such as 82 and 83 (FIG. 3 end view) are shaped so that togetherthey define open-ended cylindrical channels such as channel 84 withsubstantially enclosed circular cross-sections forming 270° arcs, eachopened at a mouth 85 on an inner face of its repeller disc.

By rotating the repeller assembly 30, most of the liquid attempting totravel downward and through the narrow passageway 64 toward the motor isforced into the channels 84 which reverses the direction of the liquidback toward the impeller assembly 25. It is important that the channels84 not be completely enclosed. The combination of the liquid beingpushed by the rotating repeller assembly 30 against the backplate 42, 65or 66 imposes on the liquid an upward spiral motion which expels theliquid back up through the channels 84. The backplates 65, 66 and 42 arestationary and become a source of friction which is necessary for theliquid to assume the spiraling motion. This vortex type energy imposedon the liquid is similar to that imposed on the liquid by the back pumpout vanes 86 of the impeller 46.

In the present embodiment, the parallel disk members 50 and 51 defineten radially extending circular channels 84 in each vane arrangement 80and 81, with each channel having a length of 7.5 inches. Each disk 70and 71 is not limited to 7.5 inch channels, but commonly includes lengthsuch as a 7.5 inch diameter with a cross-sectional width or diameter ofapproximately 0.5 inches. The repeller disks commonly include lengthsbetween six and thirteen inches. Also, as few as four to six vanes is areasonably functional configuration. The size and number of variouselements of the pump are based on the type of liquid pumped and thepressure generated.

The drainage ports and plugs 59 and 63 of the preferred embodimentpermits one to empty the chambers such as repeller cavity and a cavity87 which collects liquid or gas being pumped which traverses thepassageway 64 past the impeller. The liquid which could enter cavity 87may do so in a number of manners: the liquid may traverse the entirenarrow repeller passageway without ever entering a cylindrical channel84; there is a failure in the repeller assembly 30; or, if the pressureof the liquid entering the repeller assembly 30 is so great as toovercome the substantial vortex energy generated by the repellerassembly.

After entering the cavity 87, the barrier preventing the liquid fromreaching the motor 21 is the triplex seal arrangement 100 (FIG. 5). Thistriplex seal 100 is made up of a circular, rotating disc or flange 90which has a cavity 87 facing side 91 and a sealing side 68 defining asealing surface. The flange or disc 90 is coaxial with and mounted onthe shaft 23 and thus rotates at the same rate along with the impellerand repeller. The actual sealing of the triplex seal 100 is the slidingengagement of a plurality of cylindrical sealing surfaces 92, 93 and 94on the rotating flange 90 mating and forming cylindrical mating surfaceswith a plurality of cylindrical sealing surfaces facing and engagingsurfaces 92, 93 and 94, and provided by cylindrical tubes 96-98,coaxially with shaft 23. The initial engagement at the mating sealsurfaces of the tubes and flange 90 is created by the combination ofspring elements 100, 101 and 103 and rods or anti rotation pins 104, 105and 106, respectively. Equally spaced and coaxially arranged around thetriplex seal arrangement at each tube, there are ten resilient springsin this embodiment for each of the three mating sealing surfaces. Thespring pressure is light and forms only a sliding contact withsubstantially no sealing pressure at the sealing surfaces. The tubesmove longitudinally, but are stationary against rotation.

The liquid or gas being pumped which may enter the cavity 87, travelsover the right hand side of the rotating flange 90 to the outer edge ofsealing surface 92 and sealing tube 96. The liquid or gas then entersneck 110 where the liquid applies inward pressure on a flexiblecylindrical diaphragm 111 having a thickness ranging from 0.003 to 0.004inches. The amount of inward movement of the flexible diaphragm islimited by a top cylindrical shelf 112 of a cylindrical receptacle 113.The outward expansion of the flexible diaphragm is limited by bottomshelf 114 of block arrangement screwed to a mounting flange 116 fixedagainst movement by a circular flange of a circular housing or casingportion 119. Casing portion 119 is bolted by eight circumferentiallyarranged bolts at each end, as shown at 710 and associated casingflange.

During operation of the pump, the flexible diaphragm 111 has twopossible positions. One position is assumed when the diaphragm 111 ispressed against the top shelf 112, and the other when the diaphragm 111is pressed against the bottom shelf 114. While having the diaphragmassume a position between the two mentioned positions is theoreticallypossible, practically it does not occur in use of the pump.

The position assumed by the diaphragm 111 defines the area at a pressureapplying surface 120 to which pressure is applied to the sealing tube96. The cylindrical diaphragm 111 is mounted by a clamp provided byclamping rings or blocks 116, 116a and 116b, all sealed by resilientO-ring seals 130 on flange 119. In addition, the diaphragm 111, 171 and174 each serve as either a primary or secondary seal, depending ontemperature requirements. The sealing tube 96 and diaphragm 111 aremounted at the flange end 119 by bent over continuous, circular, metalcollars or stabilizer holders 140 and 141 welded, press fitted orotherwise attached to each other as shown at FIG. 5.

The area of surface 120 comprises that portion of a circular holder 140which is either between the cylindrical, longitudinal plane defined bythe bottom shelf 114 and the flexible diaphragm 111 in a radiallyoutward position, or between the cylindrical, longitudinal plane definedby the top shelf 112 and the diaphragm 111 in the inward position. Byextending the distance between the top shelf 112 and the bottom shelf114, one may vary the pressure applying cylindrical area of surface 120.The seal pressure applying surface 120 is made up of the entire face ofthe collar 140 facing the motor, but its area is varied by movement ofthe diaphragm as described. The diaphragm can be of rubber, plastic orany resilient material including metals.

The pressure applying area dimensions are selected based on the amountof closing force desired on the sealing surface of tube 96 against theflange or disc sealing surface 92. In the present embodiment, the area120 is 75% of the facing mating surface of the sealing tube 96 whichengages the sealing surface 92 of the rotating flange 90. With moreviscous liquids, a greater percentage pressure applying surface may benecessary. By creating a system wherein the pressure applying surface isalways proportional to the sealing surface, one minimizes the frictionalforces while maintaining a desired fluid seal across the mating sealingsurfaces of the flange 90 and tube 96. Continuous circular sealing rings160, 161, 169 abut the tubes 96, 97, 98 respectively and are mounted onand fixed to the sealing surface of flange 90, preferably in circulargrooves as shown in FIG. 5.

Chambers 162 and 163 are formed between the sealing tubes and may befilled with a gas or liquid as desired through injection ports 164 and165 which define circular bores leading to the chambers. Often, one ofthe chambers 162 or 163 will be filled with a second liquid other thanthat being pumped. Such liquid can be used to apply pressure to theassociated diaphragm to counteract or adjust the effect of fluid whichmay fill chamber 87 and act on sealing surface 92 and the outside ofdiaphragm 111 Liquid or gas in backup chamber 162 and/or chamber 163 canbe used to monitor pressure in each chamber and/or detect leakage ineach chamber. The injection ports 164 and 165 may also be used tomonitor the amount of pressure in chambers 162 and 163 respectively, andto determine whether greater pressure is required to prevent the sealsformed at sealing surfaces 92, 93 and 94 from opening.

While only the diaphragm 111 and its associated tube 96, with mating andsealing surfaces and holders as claimed, has been described. Identicalparts are used and duplicated to form the triplex seal. Thus, diaphragms170 and 171 are mounted through mounting rings or holders 172 and 173,bolts 174, holders 180, 181, 182 and 183 to form the triplex seal havingdual chambers 162 and 163, with each tube having its backup diaphragm soas to provide a pressure applying surface whose area can be varied tovary the sealing pressure at the mating surfaces of each tube and eachsliding contact surface with the disc 90.

The right hand side of the disc 90, as shown in FIG. 5, is first exposedto the fluid that passes the repeller, filling chamber 87 and alsoapplies a pressure to the diaphragm and to the pressure applying surface120. The pressure applying surface of tubes 97 and 98 are only activatedby pressure within the chamber 162 and 163, and only by predeterminedpressure caused by filling these chambers if desired. In the only caseof other pressure being applied in chambers 162 and 163, there would bea differentiation in pressure which is predetermined in the chambers ifthere is leakage through the first tube 96, causing a different pressureon the rear pressure applying surface of tube 97 and, similarly, ifthere is leakage of fluid from chamber 162 through tube 97, there wouldthen be a different pressure on the pressure applying surface of tube98. In some cases, the liquid pressure in chamber 87 may be thepredetermined pressure applied in chambers 162 and 163.

In some cases, a single tube 96 and diaphragm 111 can be used and thechamber 162 is the only chamber which is, in fact, a circular chamberwith no tubular arrangements defined by tubes 97 and 98. Similarly, adouble seal can be formed or quadruple or higher numbers of rotatingsealing surfaces can be used.

The flange 90 is fixed to the pump shaft 23 and suitable resilientO-rings, gaskets or other means are used to provide conventionalpositive seals as at 190.

If unwanted, excess liquid pumped passes through the triplex seal, thenext barrier which the liquid meets is the piston seal arrangement 32(FIGS. 1, 6). A cylindrical piston head 180 has a cap 181 which isthreadably engaged to a piston body 182 by screw threads 183 and 184.The piston body 182 has additional screw threads 185 to engage the screwthreads of a cylindrical casing portion 186 of main casing 22. A pistonstem 190 is fixed and attached to the piston cap 181 and extends intothe piston head 180. The stem 190 is held stationary with the cap by adisc seal 400. A resilient O-ring seals a sliding reservoir disc 191.The piston body opening 194 coincides with a channel bore 195. Thechannel 195 extends into a circular reservoir or pressure applyingchamber 196 which forms a ring coaxial with the shaft 23 and is boundedon one side by an axially slidable circular ring holder 197 whichsecures an axially sliding sealing tube 198 in position.

The cylindrical tube 198 is identical to tubes 96, 97 and 98 and has thesame sealing function at a circular sealing surface of a rotatingcylindrical sealing surface 210 of a flange or disc 201 which is fixedto shaft 23 by threaded pin 202 and O ring seal 203. The reservoir orchamber 196 is concentric with the shaft 23 tube and pressure ofhydraulic liquid therein applies pressure to sealing surface 200. Thestationary sealing surface or face 210 of the tube mates with acylindrical sealing and mating surface 200 forming a seal therebetween.To prevent the rotation of the longitudinally slidable tube, a group ofanti-rotational pins 211 having circular or non-circular cross-sectionsextend through the reservoir 196 and into the staionary holder 197. Thepins 211 are four in number arranged in a circle coaxial with both theshaft 23 and tube 198 and spaced equidistantly around the piston sealarrangement. The number of pins 211 can vary with two or more such pinsnormally used. The tube 198 is secured to holder 197 which is attachedto a circular flange portion pump casing 186, against rotationalmovement. The tube 198 and holder 197 slide on pins 211 when pressure isincreased or decreased in circular reservoir 196.

The rotary sliding surface 200 rotates at the same speed as the shaft23. The strength of the seal created by the face 200 and the relativelyrotary face of the tube is increased by screwing down the piston cap 181to create more pressure in the reservoir through the piston 180. Thisincrease in pressure translates to more pressure on the rear pressureapplying face of holder 197, which increases the pressure on the matingsurfaces of the tube 198, a mating circular disc 201, as the discrotates, as well as when it is stationary. The disc 201 provides themating sealing surface 200.

The piston seal may only be useful if the pumped liquid or gas haspassed through the triplex seal arrangement and repeller into chamber204. The friction that is created by sealing the rotary face of disc 201against the stationary face of the tube 198 can decrease the efficiencyof the pump and thus the piston seal may be deactuated or adjusted asdesired by means of the piston pressure in particular situations. Byattaching a pressure gauge to one of the injection ports 164 or 165, onemay automatically activate the piston seal if escape of the liquidbeyond the triplex seal arrangement is detected to be imminent. Thus,the user need only allow the piston seal to actuate when necessary, ifthis is desired.

Alternately, the piston seal can be maintained at a relatively low sealclosing pressure at all times to maintain the oil within the bearingsfrom leaking out to chamber 204.

Turning now to the oil mister assembly 34, as best shown in FIGS. 7-9, acasing 186 defines a chamber 250 surrounding the shaft 23 and having alower well 187 which can be filled with a lubricating oil or otherliquid. Conventional rotating bearings such as ball bearings are shownat 251 and 252, coaxial with and mounting the motor shaft 23 forrotation. The bearings each are of conventional ring design with aplurality of sliding balls such as 252, 253, and 254 coaxially arrangedabout the shaft 23, as known in the art. The ball bearings allow freerotation of the shaft.

A dispenser 260 is fixed to the shaft for rotation therewith on a sleeve261. The dispenser 260 has nozzles formed by bores 262 and 263 onopposed sides of the dispenser body. The bores 262 and 263 are eachassociated with a tubular passageway 264 having scoops in the form ofhood 265 and 266 which are mounted on a disc of sleeve 261 keyed to theshaft 23. The disc defines the scoops as entraining means for directinglubricating liquids to their respective nozzles. The nozzles aredirected outwardly and forms means which are mounted in a pathwaydefined by the dispenser disc. Since the nozzles are directed towardseach rotary seal, on opposed sides of the disc or dispenser, as theshaft rotates by rotating the scoops of the disc, a controlled flow ofliquid or mist is automatically passed to the bearings. By suitableselection of the scoop and nozzle arrangement, one can direct the fluidexactly where one wants to direct the fluid, that is, toward the ballbearings, without immersing the bearings in fluid, yet allowing asufficient amount for lubrication.

Proper selection of the scoop's rotation and nozzle means also allows amisting action to mist the lubricating fluid such as oil. Thus, a spraycan be directed at the ball bearings directly where needed from opposingfaces of the dispenser in a rotary motion, thereby misting the ballbearings without causing liquid filling which might hamper the rotarybearing action.

FIG. 9 illustrates the action of the scoop in a cross-section as thedispenser rotates. Direct lubrication of the bearing could flood thebearing assembly and increase friction. Preferably, misting action isdesired and proper placement of the dispensed fluid or liquid as theshaft rotates is preferred.

In an alternate embodiment of the mist arrangement shown in FIG. 10-12,the dispenser 270 is in the form of a disc which has an encircling groveperpendicular to the axis of the shaft. The grove is provided withnozzle means 271 and 272 and a scoop action provided by channels 273 and274 which rotate in the fluid chamber as shown. Thus, the nozzle meansprovide for flow of oil, preferably in misted form, towards the bearingson opposed sides of the dispenser 270.

In still another arrangement for providing oil to the opposed rotarybearings, a coaxially arranged dispenser 280 carries a plurality ofbristles 281 which are mounted on the shaft 23 for rotation therewith.As the bristles, which can be wire bristles, are rotated through thetrough carrying the oil, the oil is picked up, misted and directedtoward the opposed rotary bearings. The bristles can be mounted on asuitable disc sleeve 290 in any conventional manner known in the art. Inthe present case, they are adhesively adhered through adhesive means notshown. Welding, soldering and the like can be used. The wire bristledispenser of FIGS. 13 and 14 provides for a fine mist which isparticularly preferred.

Turning now to the next section of the pump of this invention, the pumpmotor 21 has a casing portion of housing 22 of any conventional designand has its shaft, indicated at 23, passing through the motor.Conventional bearings 324 are provided as known in the art, as is arotary end seal coaxial ring 326. The motor drive shaft 23 has a reduceddiameter end 327 mounting a doughnut-shaped magnet 328. The magnet andshaft are enclosed in an end cap 329 bolted to and sealed to the motorend by 8 circularly, evenly spaced, arranged screw threaded bolts 330,with sealing O-ring resilient gasket 331 of a suitable neoprene or otherrubber, as can be used for any of the seals of this invention. O-ringseals can also be of metal as known in the art.

Because the end cap 329 is used, the motor is totally sealed. The cap isof a non-magnetic material such as plastic as known in the art. Nonmagnetic metals can also be used for the cap. Thus, the sealed motorprovides a further barrier. Should any hazardous liquid or gas escapealong the shaft to the motor, it will be stopped by the cap.

The doughnut 328 provides for actuating through the drive shaft 23, acooling fan shown at 400. The fan 400 is mounted by bolt 701 on a rotarybearing 401 which is fixed by a shaft 402 to an outer flow directingcasing 403, 8 bolts 404 and washer standoffs fix the casing or cap 403to the motor casing. Air passageways are provided as shown by arrows 410to allow cooling environmental air and other fluid from the fan 400 tobe directed from the environment through holes 700 along the motorcasing, as shown by the arrows 410. The fan 400 can be any standard fanblade. A magnetic mass, as of iron where a magnet is used for thedoughnut 328, is provided in the form of an inset encircling ring 420.Thus, the magnetic mass 420 is actuated by rotation of the motor shaft23 through the doughnut 328 of magnetic means as known in the art, toprovide a cooling action to the motor, yet have the cooling fan sealedand environmentally protected from possible escape of fluids through thepump.

As known in the art, the magnet and iron or magnetic mass can beswitched with either mounted on the shaft or the fan blade. Opposed poledrive magnets can be used as known in the art.

Mounting support brackets 800, 803 can be used along with adjustingbolts and mounting bolts 802. Conventional stands or holders of knowntypes can be used.

While specific embodiments of this invention have been shown anddescribed, many variations are possible. In all cases, it is desired toprevent fluid or gas escape along a drive shaft when a pump is operatedby a drive motor. This is particularly important when pumping hazardousfluids. In some cases, individual components of this invention can beused in other rotary sealing or fluid impeding devices, as for example,sealing rotary shafts of compressors which are considered pumps, orother rotating devices.

While specifics have been described, various sizes, dimensions, pumpingvalues and the like can be used, as will be obvious to one skilled inthe art. Generally, pumps are used for pumping hazardous fluids underratings of various EPA and OSHA regulations described in public law101-DTD November 1990. This is exemplery but not inclusive jof alldangerous, toxic, carcinogenic, and volatile compounds. While allcomponents of the pump are preferably metal, except as specificallydescribed, many materials can be used as known in the art. The tubeswhich form the sealing surfaces can, for example, be formed of tungstencarbide, carbon, silicone carbide or other materials. Similarly, theblocks or rings which form the mating sliding seal surfaces can beformed of the same materials or different materials, including carbon,tungsten carbide, silicone carbide and metals. In some cases, slidingseals can be formed between polytetrofluoroethylene, Kel F (atrademarked product of DuPont, Wilmington, Del.) or other low frictionmaterials.

Particularly with regard to the triplex seal, a single sealing surfaceof an enclosing circular seal can be formed by a single tube anddiaphragm arrangement with limiting stops on either side of thediaphragm. The particular seals of this invention can be used alone, incombination, or in any combination of parts enclosed herewith.Obviously, if a single seal or more than one barrier means is eliminatedfrom the pump, its sealing function will be lost but other seals remainas described.

The fact that the pump can use ball bearings for the opposed bearings ofthe drive shaft, thus avoiding sleeve bearings, and the fact that aseries of drain plug can be used to provide simple and complete drainageof fluid in the pump safely, prior to tear down of the pump for cleaningand repairs, is particularly useful when pumping fluids which may haveparticles which would otherwise perhaps obstruct sleeve bearings orcause problems in pumps of this nature.

While circular sealing surfaces have been described, disc and circularflanges all mounted coaxially with the shaft, or other configurationscan be provided as known in the art. Thus, the shaft and casing need notbe of circular cross-section, but can be of square or irregularcross-sections if desired. In all cases, the sealing surfaces areencircling about the shaft to fully seal the shaft against fluid flowfrom the right hand end to the left hand end of the pump as shown inFIG. 1. Although the casing is a multipart casing bolted together usingsuitable seals as known in the art, casing design can vary greatly. Insome cases, repellers can be eliminated and seals alone or a single sealused to prevent damage to the fan motor and environment by fluids pumpedby the pump of this invention.

It is not intended that the scope of this invention be limited to anysingle embodiment illustrated and described. Rather, it is intended thatthe scope of the invention be determined by the appended claims andtheir equivalents.

What is claimed is:
 1. A motor driven pump comprising:an environmentallyleak-proof, motor housing having located therein a motor for rotatablydriving a rotating shaft, said shaft extending from said motor and beingsealed within a pump housing; said pump housing being sealably connectedto said motor housing, said pump housing including a pump chamber inwhich fluid is pumped between a fluid inlet and a fluid outlet; a fluidimpeller disposed within said pump chamber, said impeller for pumping afluid from said fluid inlet to said fluid outlet, said impeller beingaffixed to said rotating shaft; a fluid passageway disposed between andcommunicating with said pump chamber and a fluid chamber, said fluidchamber circumferentially surrounding said rotating shaft; a fluidsealing device disposed axially along said shaft between said fluidchamber and said pump chamber, said fluid sealing device for inhibitingthe flow of fluid from said pump chamber toward said fluid chamber, andwherein said sealing device circumferentially surrounds said rotatingshaft; a drainage orifice defined in said pump housing, said drainageorifice being defined within the bottom portion of said fluid chamber soas to allow fluid passing into said fluid chamber to flow from saidchamber by way of gravity through said drainage orifice, therebypreventing said fluid from making its way into said motor housing; anannular fluid seal disposed axially along said shaft between said motorand said fluid chamber, said annular fluid seal including a rotatingflange affixed to said shaft so as to rotate therewith and a stationaryannular engaging member, said stationary annular engaging member havingan engagement surface for sealingly engaging a radially extendingrotatable sealing surface of said rotating flange; and annular bearingmeans disposed axially between said motor and said annular fluid seal,said bearing means for rotatably supporting said shaft.
 2. A pumpbearing lubricating mechanism disposed within a pump lubricating chamberfor simultaneously providing lubrication to two coaxially located spacedapart, substantially coaxial rotary pump shaft bearings, said mechanismcomprising:a dispenser mounted coaxially with said coaxially alignedrotating bearings, said dispenser being mounted for rotation in a liquidreservoir, said dispenser being operably engaged with a central shaftmounted for rotation between said rotary bearings, plural nozzle meansmounted in a pathway defined by said dispenser, with at least one nozzlemeans directed to one of said rotary bearings and a second nozzle meansdirected to a second of said rotary bearings, said dispenser havingmeans for entraining a liquid within said liquid reservoir and bringingsaid liquid to said nozzles to dispense said liquid from said nozzlesdirectly to each of said rotary bearings.
 3. A mechanism in accordancewith claim 2, wherein said dispenser comprises a plurality of bristlesacting as nozzle means.
 4. A mechanism in accordance with claim 2wherein said dispenser comprises a circular disk having an outercylindrical surface acting to entrain said liquid and carry said liquidto said nozzles.
 5. A mechanism in accordance with claim 2, and furthercomprising:said dispenser comprising a rotating disc coaxially mountedon said shaft, said disc defining said entraining means in the form of aplurality of scoops for directing liquid to said nozzles.
 6. A mechanismin accordance with claim 5, wherein said disc defines a passageway tosaid nozzles and said nozzles are located on opposed sides of said disc.